Tinting machine with positive displacement pump

Abstract

A tinting machine (1) for metering, dispensing and mixing tinting pastes to produce paint having a desired color or quality. The tinting machine includes a plurality of dispensing units (8), each dispensing unit including a container (4) for containing a tinting paste and a pump (9). The dispensing units are selectively movable to a dispensing position. The tinting machine further includes an actuator (20) that engages a selected one of the dispensing units when it is in the dispensing position. The actuator includes a primary gripper (40) for engaging the pump for rapid dispensing and a secondary gripper (50) for engaging the pump for precise dispensing.

Description

Technical Field

[0001] This disclosure relates to a color mixing machine including at least one positive displacement pump for accurately metering a small amount of liquid to be dispensed and for dispensing a larger amount of liquid at a faster rate. Such color mixing machines are used to dispense and mix color pastes according to a predetermined formulation of a desired paint color. Background Technology

[0002] To reduce waiting time for users to mix paints, colorants are typically dispensed using relatively large-diameter dispensing channels at relatively high speeds (typically around 0.5–1 L / min). Precise dispensing of smaller quantities requires a combination of smaller-diameter dispensing channels and lower dispensing speeds (e.g., 0.15–0.25 L / min). In addition to the effect of dispensing channel diameter on precise dispensing, the accuracy of the piston head's volumetric displacement also plays a role. When using a smaller piston head, the volumetric displacement becomes more precise. Piston pumps with two aligned piston heads of different diameters can be selectively used for faster or more precise dispensing as needed. US 2009 / 0236367 discloses an example of such a pump. This system uses a pump that nests a smaller piston head within a larger piston head. This construction is relatively complex and costly to manufacture. The required bias spring causes undesirable side effects.

[0003] EP 3 249 222 A1 discloses a colorant dispenser having a pump and a cylindrical valve core with multiple channels. The channels create high flow resistance and make it difficult for trapped air to escape from the liquid. The large volume between the piston head and the dispensing outlet results in low dispensing accuracy. The dispensing process requires numerous steps.

[0004] US 4,964,534 discloses a dual-piston head colorant dispenser having a small piston head for dispensing a smaller amount that can move within a larger piston head for dispensing a larger amount. Summary of the Invention

[0005] The purpose of this invention is to provide a robust and durable dispenser that combines high dispensing speed with high precision, without the aforementioned drawbacks of existing technology systems.

[0006] The object of this invention is achieved by a tinting machine for metering, dispensing, and mixing tinting paste to prepare paint with a desired color or quality. The tinting machine includes multiple dispensing units. Each dispensing unit includes a container or tank for holding the tinting paste and a pump for drawing the tinting paste from the container. The dispensing unit can be selectively moved to a dispensing position. The tinting machine also includes an actuator that engages with a selected dispensing unit when it is in the dispensing position. The actuator includes a main clamp for engaging with the pump for rapid dispensing and a secondary clamp for engaging with the pump for precise dispensing. Thus, a relatively simple and robust dispenser can be used without complicating the structure of valves or other components.

[0007] For example, the pump can be a positive displacement pump, such as a piston pump, having a main displacement member and a secondary displacement member. The main clamp is connected to the main displacement member when the dispensing unit is in the dispensing position to move the main displacement member in the pumping direction, and the secondary clamp is connected to the secondary displacement member when the dispensing unit is in the dispensing position to move the secondary displacement member in the pumping direction. Thus, the actuator can be used to directly operate both displacement members.

[0008] In one embodiment, the primary gripper includes a slot that receives a geometrically matching portion of the primary displacement member when the displacement pump moves to the dispensing position, and the secondary gripper includes a slot that receives a geometrically matching portion of the secondary displacement member. Thus, the dispensing unit, moved to the dispensing position, automatically engages with the actuator and can be immediately activated to dispense a metered amount of the selected colorant.

[0009] For example, the main gripper can move together with the auxiliary gripper, and the auxiliary gripper can move relative to the main gripper in the pumping direction.

[0010] For example, one end of the main gripper engages with the main displacement member, and the opposite end has an annular wall that receives the auxiliary gripper in a manner that allows it to slide along the pumping direction. For this purpose, the auxiliary gripper may have a profile that slides into the inner contour of the annular wall. Thus, the auxiliary gripper is nested within the main gripper, allowing the auxiliary gripper and the main gripper to move together when a larger volume of feed is required. It has been found that the auxiliary displacement member can move in a manner that minimizes mechanical backlash.

[0011] For example, the annular wall can be a non-circular annular wall sealed by a cover plate including a driver and a threaded spindle, such as a stepper motor. The threaded spindle extends coaxially from the cover plate toward the sub-gripper, and is driven by the driver to rotate about its longitudinal axis. The sub-gripper has a central threaded opening for receiving the threaded spindle. The rotation of the threaded spindle causes the sub-gripper to move linearly along the pumping direction, i.e., along the longitudinal axis of the threaded spindle.

[0012] In one specific embodiment, the positive displacement pump is a piston pump, and the main displacement component is a main piston head connected to the main piston rod, and the secondary displacement component is a secondary piston head having a secondary piston rod that can slide telescopically within the main piston head. One end of the secondary piston head is connected to the secondary piston rod, which can slide telescopically within a central opening extending through the main piston rod.

[0013] In one specific embodiment, the secondary piston rod has an outer end that extends relative to the outer end of the primary piston rod at all locations along the metering path of the secondary piston head.

[0014] For example, the outer ends of both the main piston rod and the auxiliary piston rod may be provided with flanges or protrusions for engaging with corresponding grippers. When the dispensing unit moves to the dispensing position, the gripping portion can be received within a matching slit in the gripper.

[0015] For example, the distribution unit can be supported on a movable platform, such as a turntable.

[0016] For example, the positive displacement pump can be a piston pump, plunger pump, bellows pump, etc.

[0017] The above aspects will be described in more detail below with reference to the accompanying drawings, which illustrate several embodiments by way of example, and further details and benefits will be explained. Attached Figure Description

[0018] Figure 1A A three-dimensional view of the dispenser is shown;

[0019] Figure 1B Shown without cover Figure 1A Distributor;

[0020] Figure 2 The distribution unit of the distributor in Figure 1 is shown;

[0021] Figure 3A It shows Figure 2 A cross-sectional view of the distribution unit, in which the piston head and valve are in a stationary position;

[0022] Figure 3B This shows the valve in the suction position. Figure 3A Allocation unit;

[0023] Figure 3C This shows the valve in the precise dispensing position. Figure 3A Allocation unit;

[0024] Figure 3D The valve is shown in the quick-dispensing position. Figure 3A Allocation unit;

[0025] Figure 4A It shows Figure 2 A cross-sectional view of the distribution components, in which the main piston head and the auxiliary piston head are pushed in;

[0026] Figure 4B It shows Figure 2 A cross-sectional view of the delivery assembly, wherein the clamp holds the piston head in... Figure 4A The location shown;

[0027] Figure 5A It shows Figure 2 A cross-sectional view of the distribution assembly, showing the main piston head being pushed in and the secondary piston head moving upward;

[0028] Figure 5B It shows Figure 2 A cross-sectional view of the delivery assembly, wherein the clamp holds the piston head in... Figure 5A The location shown;

[0029] Figure 6A It shows Figure 2 A cross-sectional view of the distribution components, in which the main piston head and the auxiliary piston head move upward together;

[0030] Figure 6B It shows Figure 2 A cross-sectional view of the delivery assembly, wherein the clamp holds the piston head in... Figure 6A The location shown. Detailed Implementation

[0031] Figure 1A and Figure 1B A color mixing machine 1 for mixing and dispensing paint products is shown. The color mixing machine 1 has a dispenser housing 2 with a cover 3. Figure 1B A color mixing machine 1 without a cover 3 is shown to illustrate its internal components. The internal components of the color mixing machine 1 include containers or tanks 4 arranged in a concentric circular array. Each container 4 contains a color paste or colorant of a specific color. The containers 4 are placed in an upright position on a turntable capable of rotating about a vertical axis coaxial with the circular array of containers 4. The color mixing machine 1 also includes a platform 6 for positioning paint tanks or similar receiving containers (not shown).

[0032] The color mixing machine 1 includes a control unit (not shown) having a user interface (such as a touchscreen) in communication with the control unit, enabling an operator or user to input a desired paint color. When the user inputs a desired paint color, the control unit determines a paint formula that matches the selected paint color, for example, by selecting the paint formula from a database. The determined paint formula consists of tinting paste or a mixture of tinting pastes available in the corresponding containers 4 of the color mixing machine 1, and optionally consists of a base paint. The control unit controls the rotation of the turntable to sequentially position the containers 4 containing the desired tinting paste at dispensing positions above the paint tanks on the platform 6, and controls the dispensing of the tinting paste one by one according to the selected paint formula.

[0033] Each container 4 is Figure 2 A portion of the dispensing unit 8 is shown in a longitudinal sectional view. The dispensing unit 8 includes a container 4, a piston pump 9, and a three-way valve 10.

[0034] In the exemplary embodiment shown, container 4 includes a longitudinally cylindrical shell 11 having a top end 12 and a bottom end mounted to the turntable. An outlet 13 is provided at the bottom end of container 4. A stirrer 14 extends coaxially from the bottom end to the top end 12 within the internal space 15 of container 4.

[0035] exist Figure 2 In this process, the piston pump 9 of the dispensing unit 8 engages with the actuator 20. The actuator 20 is not part of the dispensing unit 8, but has a fixed position at the dispensing position within the color mixing machine 1, where it engages with the piston pump 9 of the dispensing unit when the dispensing unit 8 moves to the dispensing position above the platform 6.

[0036] The piston pump 9 includes a pump cylinder 16 and a main piston 17 having a main piston head 18. One end of the pump cylinder 16 is connected to the valve housing 19 of the valve 10, and the opposite end is closed by an end cap 21. The main piston head 18 is capable of reaching a lower position in the valve housing 19 along the main stroke within the pump cylinder 16 in the pumping direction P. Figure 2 (As shown) slides between a higher position at a certain distance from the valve housing 19. The main piston head 18 is connected to a hollow tubular main piston rod 22, which extends through an opening 23 in the end cap 21 at all positions of the main piston head 18 during its full stroke. The free end of the main piston rod 22 is provided with a flange 24, which is arranged and shaped such that when the turntable 5 rotates to move the dispensing unit 8 to a dispensing position above the platform 6 for supporting the paint can, the free end engages with the actuator 20. The opposite ends of the main piston rod 22 extend coaxially through the main piston head 18, wherein the outer end of the main piston rod 22 is flush with the surface of the main piston head 18 (see also). Figure 3A ).

[0037] like Figure 3A As shown in more detail, the auxiliary piston 25 is arranged within the tubular main piston rod 22. The auxiliary piston 25 is capable of moving within the tubular main piston rod 22 along a precision stroke. Figure 3A The lower position shown slides between a position inside the tubular main piston rod 22 at a certain distance from the main piston head 18, at which the lower end of the auxiliary piston 25 is aligned with the lower end of the main piston head 18. The inner wall of the tubular main piston rod 22 is shaped to form a shoulder 26, which forms a stop for the auxiliary piston 25, thereby defining the end of the precision stroke.

[0038] The secondary piston 25 includes a secondary piston head 27 connected to the secondary piston rod 28. For example... Figure 2 As shown, the secondary piston rod 28 extends upward from the secondary piston head 27 to protrude from the flanged tip 24 of the primary piston rod 22 at each position of the secondary piston 25 during the precision stroke. The secondary piston rod 28 has a free tip with a flange 29 (see...). Figure 2 The free tip is shaped and arranged to engage with actuator 20 as described below.

[0039] Figure 3A -D shows the lower end of the piston pump 9 connected to the valve housing 19, with the valve 10 in different positions. The valve housing 19 has a container opening 30 communicating with the container 4, a pump passage 31 communicating with the piston pump 9, and a dispensing opening 32 for dispensing tinting paste into the paint tank on the platform 6. The valve housing 19 houses a valve body 33 having a central passage 34 and three radial passages: a first dispensing passage 35, a second dispensing passage 36 with a diameter larger than the first dispensing passage 35, and a third dispensing passage 37 with a diameter smaller than the first dispensing passage 35. By rotating the valve body 33 within the housing 19, the radial dispensing passages 35, 36, and 37 can be selectively aligned with the dispensing opening 32.

[0040] At any position of the valve body 33, the central channel 34 is always in fluid communication with the pump channel 31 via the interior of the valve housing 19 surrounding the valve body 33.

[0041] Figure 3A The valve body 33 in the closed position is shown, wherein all radial passages 35, 35, 37 are closed by the inner wall of the valve housing 19. A first sealing ring 30A prevents leakage to the container opening 30, and a second seal 32A prevents leakage to the dispensing opening 32.

[0042] Figure 3B The valve body 33 is shown in the suction position. In this position, moving the main piston 17 upward will draw liquid from the container 4 into the pump cylinder 16 via the container opening 30, the second distribution channel 36, the central channel 34, the interior of the valve housing 19 surrounding the valve body 33 (and partly via the first distribution channel 35), and the pump channel 31.

[0043] To precisely dispense smaller or larger quantities, the valve body 33 is rotated to... Figure 3C The position shown is such that the small dispensing channel 37 is aligned with the dispensing opening 32 in the valve housing 19, and the flow path to the container opening 30 is closed by the valve body 33 and the sealing ring 30A. As the main piston 17 and / or the auxiliary piston 25 move downward, liquid flows from the inside of the pump 9, the pump passage 31, and the valve housing 19 into the central passage 34 of the valve body 33, and finally flows through the small dispensing channel 37 and the dispensing opening 32.

[0044] To dispense smaller or larger amounts of toner more quickly, the valve body 33 is rotated to... Figure 3D The position shown. In this position, the large distribution channel 36 is aligned with the distribution opening 32 in the valve housing 19. As the main piston 17 and / or the auxiliary piston 25 move downward, liquid flows from the inside of the pump 9, the pump channel 31, and the valve housing 19 into the central channel 34 of the valve body 33, and finally flows through the large distribution channel 36 and the distribution opening 32.

[0045] Dispensing can also be performed via a first dispensing channel 35 with a medium diameter, for example, if the specific rheological properties of the dispensed toner make other dispensing channels 36, 37 less suitable.

[0046] Figure 4A The lower portion of valve 10 and pump 9 is shown, with the main piston 17 and auxiliary piston 25 pushed downwards. This position is the resting position of the main piston 17 when the dispensing unit 8 is not in the dispensing position, and it is also the starting position of the suction stroke (when valve body 33 is in the dispensing position). Figure 3B (as shown in the figure) and the end of the dispensing stroke (when valve body 33 is in the position shown ... in the figure) Figure 3C or Figure 3D (when in position).

[0047] Figure 4B This is a cross-sectional view of actuator 20 along a plane extending through the axis of rotation of the turntable and centered through the plane of actuator 20. Actuator 20 has a main gripper 40. The main gripper 40 has a main slot 41 extending along the entire width of the main gripper 40 (i.e., along a direction perpendicular to the plane of the drawing). Although actuator 20 has a fixed location at the dispensing position within the color mixing machine 1, when the turntable rotates the dispensing unit 8 past said dispensing position, the flanged tip 24 of the tubular main piston rod 22 freely passes through the main slot 41.

[0048] The main gripper 40 is connected to a threaded spindle 42, which is driven to rotate by a stepper motor (not shown). Rotating the spindle 42 will move the main gripper 40 up or down. The main gripper 40 is also connected to a slider 43, which slides along a guide 44 parallel to the spindle 42 as the spindle 42 rotates to prevent the main gripper 40 from rotating with the spindle 42.

[0049] The upper end of the main gripper 40 includes an upwardly extending annular wall 45. In a top view, this wall is annular but not circular. The annular wall 45 surrounds an interior space 46 having an open top covered by a drive unit 47, which is specifically a secondary stepper motor that drives a secondary threaded spindle 48 that extends downward into the interior space 46 surrounded by the annular wall 45. The drive unit 47 is secured to the top of the annular wall 45 by fasteners 49.

[0050] The sub-gripper 50 is accommodated to move vertically within an internal space 46 surrounded by an annular wall 45. For this purpose, the sub-gripper 50 has a cross-sectional profile that slides into the inner contour of the annular wall 45. The sub-gripper 50 includes a sub-slot 51 extending along the entire width of the sub-gripper 50 and the annular wall 45 (i.e., in a direction perpendicular to the plane of the figures), so that rotating the turntable allows the flanged tip 29 of the sub-piston rod 28 to pass freely and unimpeded through the slot 51 and the alignment slot 53 in the annular wall 45 (e.g., see...). Figure 5B Meanwhile, when the dispensing unit 8 passes through the dispensing position, the flanged end 24 of the main piston rod 22 freely passes through the main slot 41 of the main clamp 40.

[0051] The secondary gripper 50 also includes a central threaded opening 52 for receiving the secondary threaded spindle 48. When the secondary threaded spindle 48 rotates, the secondary gripper 52 moves up or down relative to the primary gripper 40.

[0052] exist Figure 4B In this configuration, the dispensing unit 8 is positioned in the dispensing position, wherein the flanged tip 24 of the main piston rod 22 is received in the main slot 41 of the main gripper 40, and the flanged tip 29 of the auxiliary piston rod 28 is received in the secondary slot 51 of the auxiliary gripper 50. The auxiliary gripper 50 is located at its lowest point within the internal space 46 enclosed by the annular wall 45. The main gripper 40 is also located at its lowest point. This corresponds to the lowest positions of both the main piston head 18 and the auxiliary piston head 27, as shown below. Figure 4A As shown.

[0053] In order to dispense a small amount of colorant, the valve body 33 is moved to... Figure 3B The suction position is shown, which then causes the secondary piston 25 to move upward to complete the suction stroke, while the main piston 17 remains in its lowest position. This situation occurs in... Figure 5A As shown in the middle, Figure 5B The corresponding positions of the main gripper 40 and the auxiliary gripper 50 are shown. The main gripper 40 remains in its lowest position, while the auxiliary gripper 50 is raised to its highest position within the internal space 46 surrounded by the annular wall 45. In the next step, the valve body 33 is moved to... Figure 3C The precise dispensing position is shown, which then drives the secondary threaded spindle 48 to rotate and moves the secondary clamp 50 downward, and the secondary clamp 50 moves the secondary piston 25 downward to dispense the amount of dispensing paste via the dispensing opening 32.

[0054] In order to dispense a large amount of color paste, the valve body 33 is moved to... Figure 3B The suction position is shown, and then the main piston 17 moves upward to complete the suction stroke, while the auxiliary piston 25 remains in the same position relative to the main piston 17. This situation occurs in... Figure 6A As shown in the middle, Figure 6B The corresponding positions of the main gripper 40 and the auxiliary gripper 50 are shown. The main piston 17 is lifted by the main gripper 40 via the main thread spindle 42. The auxiliary gripper 50 moves together with the main gripper 40 while remaining in its lowest position within the internal space 46 surrounded by the annular wall 45. In the next step, the valve body 33 is moved to... Figure 3D The quick allocation location shown or Figure 3C The precise dispensing position is shown. The main thread spindle 42 is then driven to rotate and the main clamp 40 and the auxiliary clamp 50 move downward together to dispense the amount of dispensing paste via the dispensing opening 32.

[0055] It should be noted that the accompanying drawings are schematic and not necessarily drawn to scale, and details that are not essential for understanding the invention may have been omitted. Unless otherwise stated, the terms "upward," "downward," "below," "above," etc., refer to embodiments oriented as shown in the accompanying drawings.

[0056] This disclosure is not limited to the embodiments described above, which can be varied in various ways within the scope of the claims. For example, the vertical piston pump of the embodiments shown in the drawings can be replaced by a horizontal or otherwise non-vertical piston pump, or by another type of positive displacement pump, such as a plunger pump or a bellows pump.

Claims

1. A color mixing machine (1) for metering, dispensing and mixing color pastes to prepare coatings with a desired color or quality; in, The color mixing machine includes multiple dispensing units (8), each dispensing unit including a pump (9) and a container (4) for holding color mixing paste; The allocation unit can be selectively moved to the allocation position; The color mixing machine further includes an actuator (20) that engages with a selected dispensing unit when the selected dispensing unit is in the dispensing position; The actuator includes a main clamp (40) for engaging with the pump for rapid dispensing and a secondary clamp (50) for engaging with the pump for precise dispensing.

2. The color mixing machine according to claim 1, wherein, The pump is a positive displacement pump (9), such as a piston pump, which has a main displacement component (17) and a secondary displacement component (25). The main gripper (40) is connected to the main displacement member (17) when the dispensing unit is in the dispensing position, so that the main displacement member moves along the pumping direction (P); and The auxiliary clamp (50) is connected to the auxiliary displacement member (17) when the dispensing unit is in the dispensing position, so that the auxiliary displacement member moves along the pumping direction (P).

3. The color mixing machine according to claim 2, wherein, The main clamp (40) includes a slot (41) that receives a geometrically matching portion of the main displacement member when the displacement pump is moved to the dispensing position, and the secondary clamp includes a slot (51) that receives a geometrically matching portion of the secondary displacement member.

4. The color mixing machine according to any one of the preceding claims, wherein, The main gripper (40) is capable of moving together with the secondary gripper (50), and the secondary gripper is capable of moving relative to the main gripper (40) along the pumping direction (P).

5. The color mixing machine according to claim 4, wherein, One end of the main clamp (40) engages with the main displacement member, and the opposite end has an annular wall (45) that receives the auxiliary clamp (50) in a manner that allows it to slide along the pumping direction (P).

6. The color mixing machine according to claim 5, wherein the annular wall (45) is sealed by a cover plate comprising a driver (47) and a threaded spindle (48), the driver being such as a stepper motor, the threaded spindle extending coaxially toward the main gripper, the threaded spindle being driven by the driver to rotate about its longitudinal axis, wherein, The sub-gripper (50) has a central threaded opening (52) for receiving the threaded spindle.

7. The color mixing machine according to any one of the preceding claims, wherein, The positive displacement pump is a piston pump, and the main displacement component is a main piston (17) having a main piston head (18) connected to a main piston rod (22), and the secondary displacement component is a secondary piston (25) having a secondary piston head and a secondary piston rod capable of sliding telescopically within the main piston rod (22). One end of the auxiliary piston head is connected to the auxiliary piston rod, which can slide within the main piston rod in a telescopic manner.

8. The color mixing machine according to claim 7, wherein, The auxiliary piston rod (28) has an outer end that extends relative to the outer end of the main piston rod (22) at all locations along the metering path of the auxiliary piston head.

9. The color mixing machine according to claim 8, wherein, The outer ends of the main piston rod and the auxiliary piston rod (22, 28) are provided with flanges (24, 29) or protrusions for engaging with the corresponding clamps (40, 50).

10. The color mixing machine according to any one of the preceding claims, wherein, The distribution unit (8) is supported on a platform, such as a turntable (5).

11. The color mixing machine according to any one of the preceding claims, wherein, The main gripper (4) is operatively connected to the first drive unit, and the secondary gripper (50) is connected to the second drive unit.

12. The color mixing machine according to claim 11, wherein, The first driving device is a first stepper motor, and the second driving device is a second stepper motor with a higher resolution than the first stepper motor.

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